The presently described invention generally relates to artificial breathing devices. More specifically, embodiments of the presently described technology provide an improved ventilator apparatus.
Emergency ventilators are devices that can partially or entirely replace bag mask resuscitation devices as a manner of providing mechanical ventilation in an emergency environment. Existing devices can permit the user, such as an EMT or paramedic, to set a tidal volume (“VT”) and breaths per minute (“BPM”) and little more, if anything. These existing devices are usually driven or powered by oxygen under pressure flowing from portable compressed oxygen cylinders.
Existing hospital ventilators can be difficult to use by individuals who are not as highly trained as respiratory therapists. In addition, existing ventilators can be very expensive. Given new requirements on hospitals to prepare for events such as terrorist attacks, natural disasters or an outbreak of disease such as avian flu, adding large numbers of ventilators can be a large financial burden and having adequate trained staffing during such a crisis can be a bigger problem.
Existing ventilators typically are controlled by a complex electronic system (“electric-only ventilators”) or by a complex system of pneumatics (“pneumatic-only ventilators”). With respect to the electric-only ventilators, these devices suffer from many drawbacks. For example, electric-only ventilators usually include a fragile electronic system of circuits used to control inspiration time and fluid flow through the ventilator. As a result, these types of ventilators tend to be relatively fragile when compared to pneumatically controlled ventilators. As emergency ventilators are typically used in emergency situations, the durability of the ventilators is of considerable importance.
Electric-only ventilators also usually include electronic circuits to control and drive a complex proportioning valve to set the fluid flow through the ventilator. Controlling such a valve typically requires a considerable amount of electric power. As a result, electric-only ventilators are usually powered by a lead acid or lithium ion battery. These types of batteries are relatively heavy and are not easily accessible during emergency situations. That is, in an emergency situation, a supply of lead acid or lithium ion batteries may not be readily available. Moreover, existing electric-only ventilators can deplete a lead acid or lithium ion battery fairly quickly. Many ventilators can deplete such a battery in under eight hours.
In addition, use of such a valve typically requires one or more position feedback circuits to achieve the accuracy required of a ventilator. The added complexity of position feedback circuits only adds to the cost of these types of ventilators.
With respect to pneumatic-only ventilators, these devices tend to be more durable than electric-only ventilators (most likely because they do not include the complex circuitry of electric-only ventilators). But, pneumatic-only ventilators usually must be very closely monitored during operation. These ventilators use a system of pneumatics powered by the fluid being delivered to the patient to control timing and flow of the fluid through the ventilator. That is, the ventilators use a build up of pressure in the device as a timing function. With small leaks and/or changes in the source fluid pressure, the timing function and thus the ventilator can suffer from poor precision and/or accuracy. Pneumatic ventilators cost less than complex electronic ventilators but still cost several thousand dollars due to the pneumatic components required.
While some more inexpensive ventilators have been introduced into the market, these ventilators also suffer from drawbacks. For example, one or more of these ventilators do not include any feedback to a user of the ventilator. That is, a user cannot determine the BPM or volume of fluid being delivered to a patient. The user must externally calculate such information using, for example, a stopwatch to determine the total time of inspiration. With such ventilators, a single user cannot assist more than one person in emergency situations. The user must stay with a ventilator to continually monitor its delivery of fluid to a user.
Thus, a need exists for an improved ventilator that is cheaper to manufacture, more durable, more precise and more accurate.